"The conclusion this article reaches, based on the presented arguments, is that Evolutionary Psychology (EP) may be a contribution to psychological science at several different, important levels. First, EP allows psychologists to communicate between different areas of psychological interest, and with other branches of science relevant to psychology as a life science. Second, EP provides a well-researched, rigorously formulated theory for evaluating any other psychological theory. The theory may prevent one from suggesting abilities that could not evolve but have been suggested within almost all psychological disciplines. The versatility EP shows as a theoretical framework for disciplines as different as psychoanalysis and cognitive science, suggests that EP may succeed in integrating psychological science. It also supports the claim that EP is as theoretically valid a science as cognitive science and evolutionary biology. EP also brings to psychology the focus on a theoretically rigorous and predictive theory of Human Nature, and the functional approach, which may provide maturation from the level of mere descriptive science. At the level of generating new theories and insights about Human Nature, EP seems to have proven its worth."